Scalar gravitational wave signals from core collapse in massive scalar–tensor gravity with triple-scalar interactions

The spontaneous scalarization during the stellar core collapse in massive scalar-tensor theories of gravity introduces extra polarizations (on top plus and cross modes) gravitational waves, whose amplitudes are determined by several model parameters. Observations such scalarization-induced waveforms therefore offer valuable probes into these gravity. Considering a triple-scalar interactions theories, we find that self-coupling effects suppress magnitude thus reduce amplitude associated wave signals. In addition, self-interacting waveform shown to be negligible due dispersion throughout astrophysically distant propagation. As consequence, waves observed on Earth feature characteristic inverse-chirp pattern. Although not with on-going ground-based detectors, illustrate may detectable at signal-to-noise ratio level ${\cal O}(100)$ future as Einstein Telescope Cosmic Explorer.